The overall objective of this proposal is to contribute to a greater understanding of the immune cells involved in the prevention or pathogenesis of periodontal disease by continuing to investigate the participation of cell-mediated immune phenomena occuring in the tissues affected by periodontal inflammation. Numerous experiments suggest that the understanding of the interplay between the immune cells and the cells of the periodontium is essential to progress in the investigative area. Specifically, this proposal seeks additional support to delineate the role that sensitized or suppressors cells derived from the thymus can play on mouse gingiva when it is challenged by antigen. Established techniques of immune reconstitution along with light and electron microscopic histological procedures will be employed to determine whether the adoptive transfer of T cells sensitized or tolerized to dinitrofluorobenzene participate in periodontal disease.